1. Field of the Invention
The present invention relates to an arc welding method. More particularly, the invention relates to a welding method with high efficiency and high quality, which is featured in that in a groove an arc generating point of a filler wire (distal end of a filler wire) is oscillated in the up and down direction, and an arc power density distribution at a groove face of base material is freely controlled.
2. Description of Related Art
It has conventionally been known in arc welding that sufficient arc heat input needs to be provided to a root portion of a groove in order to prevent a weld defect such as lack of fusion at a narrow gap portion (a root portion) of a narrow gap joint of an I, V, or K type. However; when a welding method having large weld heat input is used to sufficiently melt the root portion of a groove, there poses problems of deterioration in mechanical properties and deformation of the welded joint by a thermal cycle in the welding process. It is indispensable for resolving the problem to pertinently control dispersion and concentration of heat imput in the groove.
However, although various devices have been tried conventionally, it is not easy to freely control arc heat input distribution, and welding with high efficiency and high quality by enabling the control still poses a serious problem in an arc welding method.